Who was the first National Leaguer to have his number retired?

Today’s question: The great Yankee Lou Gehrig was the first player in history to have his number retired in 1939. Which National Leaguer was honored for being the first in his league to have his number retired?

Yesterday’s answer: Super Bowl XVI –San Francisco vs. Cincinnati; Super Bowl XX – Chicago vs. New England; Super Bowl XXI – New York Giants vs. Denver; Super Bowl XXXIV – St. Louis Rams vs. Tennessee Titans are the four Super Bowls that have featured two teams that never before had won one.